The modern communications era has brought about a tremendous expansion of wireline and wireless networks. Computer networks, television networks, and telephony networks are experiencing an unprecedented technological expansion, fueled by consumer demand. Wireless and mobile networking technologies have addressed related consumer demands, while providing more flexibility and immediacy of information transfer.
Current and future networking technologies continue to facilitate ease of information transfer and convenience to users. In order to provide easier or faster information transfer and convenience, telecommunication industry service providers are developing improvements to existing networks. In this regard, for example, improvements are being made to the universal mobile telecommunications system (UMTS) terrestrial radio access network (UTRAN). Further, for example, the evolved-UTRAN (E-UTRAN) is currently being developed. The E-UTRAN, which is also known as Long Term Evolution (LTE), is aimed at upgrading prior technologies by improving efficiency, lowering costs, improving services, making use of new spectrum opportunities, and providing better integration with other open standards.
A constant goal for LTE and indeed any operating communications network is to improve coverage. In particular, one area for improved coverage is the area of delay limited services like machine type communications (MTC) and voice over internet protocol (VoIP). For example in LTE release 8, transmission time interval (TTI) bundling was introduced to improve coverage. However, TTI bundling lengthens the retransmission cycle and therefore imposes some limitations for delay limited services.
By way of example, a TTI is a timing parameter related to encapsulation of data from higher layers into frames for transmission on the radio link layer. TTI refers to the duration of a transmission on the radio link which may be used for hybrid automatic repeat request (HARQ).